Variability in meat quality traits like water holding capacity (WHC) is a major concern for producers and consumers. In the first phase of `DRIP´ we have already shown that many biological pathways including extracellular matrix receptor interaction, calcium signalling, oxidative phosphorylation, mitochondrial pathways, actin cytoskeleton signalling, PDGF signalling, EGF signalling, ERK/MAPK signalling, as well as TR/RXR activation are correlated with WHC. The combination of expression data with linkage studies offers new options to understand the biology at a global level and the genetic factors affecting the trait of interest. Expression-quantitative trait loci (eQTL) studies of genes with trait-correlated expression may provide the necessary information required for identifying genes that control quantitative phenotypes. We have identified a number of cis and trans eQTL that coincide with those of the QTL for drip loss (DRIP) identified in a F2 pig population. In order to refine these results additional selected F2 animals with maximized genetic and phenotypic dissimilarity will be used for expression profiling and genotyping. To overcome the weakness of a still limited mapping resolution within the F2-Families and to validate and confirm the biological pathways commercial populations will be used to validate and refine the results. Here, a whole genome association study for the muscle gene expression profiles of the commercial herd Pietrain x (German Landrace x German Large White) (Pix(DLxDE)) will be studied and the results obtained in this population will be compared with previously linkage studies in the F2 resource population. The list of candidate genes and linkage regions confirmed in both phase I and II will be used for further functional analysis.